Conventionally, systems for cultivating shellfish or fish in water tank (pool) with introduced seawater are known. In case of, e.g., oyster farming, there is generally a pool immersion process in which oysters are immersed in water tank for a predetermined period of time. The pool immersion process serves to remove odor by causing oysters to expel bodily waste called pseudofeces and also serves to enhance safety by causing the oysters to excrete virus such as norovirus.
Japanese Patent Application Publication No. 2014/18099 is the prior art related to the invention of the present application.